Grinding wheel feeding mechanism



April 1947- J. l. GARSIDE GRINDING WHEEL FEEDING MECHANISM Filed July28, 1945 IA l I I I swam/M .JUHN I. EARS/17E w, Mum M Patented Apr. 15,1941 UNITED STATE GRINDING WHEEL FEEDING MECHANISM John I. Garsidc,-WestBoylston, Mass, assignor to Norton Company, Worceste ration ofMassachusetts Application July 28.1945, serial No. 607,589

1 12 Claims.

This invention relates to grinding machines, and more particularly to afluid pressure operated wheel feedingmechanism.

One object of the invention is to provide a simple and thoroughlypractical hydraulically operated wheel feeding mechanism for a grindingmachine. Another object of the invention is to provide asemi-automatically controlled wheel feeding mechanism for a grindingmachine in which the wheel may be first fed intermittently to round upthe work piece, then at a slow continuous body grinding feed, and thenallowed to dwell for apredetermined finish grinding or sparking-outperiod, after which the wheel is iaiutomatically returned to aninoperative posi- Another object of the invention is to provide anautomatically operated gauge control which serves to stop the grindingfeed when the work has been ground to a predetermined size and to set inmotion a time delay relay which allows a sparking-out or finish grindingto continue for a predetermined time interval, after which the wheel isautomatically and rapidly moved to an inoperative position. Otherobjects will be' in part obvious or in part pointed out hereinafter.

The invention accordingly consists in the features of construction,combinations of elements, and arrangements of parts, as will beexemplified in the structure to be hereinafter described, and the scopeof the application of which will be indicated in the following claims.

In the accompanying drawing, in' which is shown one of various possibleembodiments of the mechanical features of this invention, is illustrateddiagrammatically the improved hydraulically and electrically controlledwheel feeding mechanism, having some portions shown on an enlarged scaleto clarify the illustration.

A grinding machine has been illustrated in the drawing comprising a baseII) which supports a longitudinally movable work table I I on the usualfiat way l2 and V-way l3. The table II serves as a support for aheadstock i4 and a rootstock (not shown) rotatably to support awork-piece IE to be ground.

A suitable traversing mechanism may be provided for longitudinallypositioning the vork table ll so that the work piece is in the desiredposition for a grinding operation. This mechanism may comprise a rackbar !6 depending from the under side of the table I I. A gear ll mesheswith the rack bar It and is mounted on the end of a shaft l8. The shafti8 is rotatably journalled in suitable bearings (not. shown) whichpreferably comprises a 1-, Mesa, 9. corpoare fined relative to the baseIt). A manually operable traverse wheel is i mounted on the outer end ofthe shaft i8 by means of which the table II may be adjustedlongitudinally relative to the baselil as desired.

A'rotatable grinding wheel 20 is supported at one end of a rotatablewheel spindle 2| which is journalled in suitable bearings (not shown) ina transversely movable wheel slide 22. The slide 22 is slidablysupported on the usual flat way and V-way -(not shown) formed on thebase II). A driving mechanism is provided for rotatin the grindig wheel28 which may comprise an electric motor 23 which is mounted on the uppersurface of the wheel slide 22. The motor 23 is provided with an armatureshaft 24 which supports a multi-V-groove pulley 25. The multi-V- groovepulley 25 is connected by multiple V-belts 26 with a multi-V-groovepulley 21 which is mounted on the end of the wheel spindle 2!.

A suitable feeding mechanism is provided for adjusting the wheel slide22 transversely relative to the base ll). This mechanism may comprise arotatable cross feed screw 30 which meshes with a half nut 3i dependingfrom the under side of the wheel slide 22. The feed screw 30 is slidablykeyed at its left-hand end in a hollow sleeve 32 which is formedintegral witha rotatable shaft 33. The shaft 33 is iournalied insuitable bearings (not shown) which are fixedly mounted relative to thebase it). A manually operable feed wheel 34 is mounted on the front ofthe machine base and is operatively connected to rotate the shaft 33 andthe feed screw to manually to adjust the position of the wheel slide 22and the grinding wheel 20 as desired.

It is desirable to provide a suitable power operated mechanism formoving the wheel slide 22 rapidly to and from a grinding position and toaid in automatically controlling the grindingfeeding movement thereof.This mechanism hydraulic cylinder 35 which is supported in iixedrelation with the 'base II). A slidably mounted piston 36 is mountedwithin the cylinder 35 and is operatively connected toa double endpiston rod 31. The lefthand end of the piston rod 3'! is rotatablyconnected to a slidably mounted non-rotatable sleeve 38 which alsorotatably supports the right-hand end of the feed screw 30. When fluidunder pressure is admitted through a pipe 3 9 into a cylinder chamber 40at the right-hand end of the piston 36, the piston 36 will move towardthe left to transmit an axial feeding movement to the feed. screw 30 anda forward feeding movement to the grinding wheel slide 22 and thegrinding wheel 28. During this movement, fluid within a cylinder chamber4| formed at the lefthand end of the cylinder 35 exhausts through a pipe42.

Control value to shift the valve 43 into its reverse position.

Dash pot-feed regulator A wheel feed regulator 55 is provided forretarding the rapid movement of the wheel slide 22 caused by the piston36. This regulator 55 is preferably a dash pot type mechanism includinga pair of dash pot pistons 56 and 51 which are arranged on diametricallyopposite sides of the piston rod 31. Compression springs are providednormally to urge the dash pot pistons 56 and 51 toward the right. Asleeve 58 is adjustably mounted on the right-hand end of the piston rod31. The sleeve 58 is provided with a flange 59 which may be formedintegral with the sleeve 58 or may be formed in two parts, as indicatedin the drawing. The flange 59 is arranged so that it will simultaneouslyengage both' of the dash pot pistons 56 and 5! when the piston rod 31 ismoved toward the left. An adjustable stop screw 60 is provided to limitthe rearward movement of the flange 59 toward the right and thusdetermine the inoperative positionof the dash pot pistons 56 and 51. Anadjustable collar 6| is threaded onto a threaded portion 62 of thepiston rod 31. This collar 6! is adjusted so that when the piston 36 hasmoved to a predetermined position in its stroke so that the grindingwheel 20 is about to engage the work piece to be ground, the collar 6|will engage the sleeve 58 and thereby start movement of the dash potpistons 56 and 5'! toward the left. Fluid within the dash pot chambersis thereby compressed and forced out through a passage 63, a needlevalve 64, and a pipe 65 into a reservoir 66. By adjusting the needlevalve 66, the speed of the feeding movement imparted to the grindingwheel 28 may be varied as desired.

In certain grinding operations, it may be desirable to cut off theexhaust of fluid through the pipe 65 thereby to stop the forward feedingmovement, as controlled by the needle valve 64, automatically in timedrelation With the movement of other parts of the grinding wheel feedingmechanism to be hereinafter described. To accomplish this result, apiston type valve 67 is provided the feed control valve 43. Anadjustable pressure relief valve 14 is provided in the pipe line 73which serves to exhaust excess fluid under pressure directly into thereservoir 12 so as to maintain the desired operating pressure within thehydraulic system.

Fluid under pressure passing through the pipe 13 enters a valve chamber15 located between the valve pistons 46 and 41 of the feed control valve43. In the position of the valve 43 as illustrated, fluid under pressureentering the valve chamber 15 passes out through the pipe 42 into thecylinder chamber 4! to move the piston 36 toward the right into aninoperative position. During this movement, fluid within the cylinderchamber 40 exhausts through the pipe 39, through a valve chamber l6located between the valve pistons 45 and 46, and passes out through anexhaust pipe 11 which conveys exhaust fluid back to the reservoir 12. Athrottle valve 16 is provided in the pipe line 11 by means of which therate of exhaust of fluid from. the feed control valve 43 may be readilycontrolled to regulate the speed of movement of the grinding wheel andits supporting slide 22 to a rearward position.

Displacement Cylinder In a plunge-cut grinding operation it is desirableto provide an intermittent rather than in the pipe line between theneedle valve 66 and the reservoir 66. The valve 57 is a normally openvalve and is normally held in the position illustrated in the drawingsby means of a compression spring. An electric pull-type solenoid 68 ispro vided automatically to close the valve 6! when the solenoid 66 isenergized in a manner to be hereinafter described.

Fluid system A fluid pressure system is provided for supplying thedesired fluid under pressure for the operating mechanisms of the machinecomprising a a, continuous infeeding movement of the grinding wheel sothat the grinding wheel 20 may be advanced by a predetermined amount andthe grinding wheel allowed to grind the work piece l5 being groundbefore the wheel 20 is again advanced. It has been found that by such afeeding mechanism, the work may be more readily rounded-up to a precisecylindrical form and size. In order'to provide a relatively slowinfeeding movement of the grinding wheel which may be operated eithercontinuously or intermittently, it is desirable to provide a suitablecontrol mechanismwhereby fluid exhausting from the dash pot cylindersmay be readily controlled as desired. In the preferred construction, adisplacement cylinder 38 is provided having a longitudinally movabledisplacement plunger 8| contained therein.

The plunger 8! is preferably actuated hydraulically by means of a piston82 which is slidably mounted in a cylinder 83. A pipe 84 connects thedash pot cylinder chambers with the displacement cylinder 88 so that asthe displacement plunger M is moved toward the left, the capacity of thedisplacement cylinder 89 will be increased, thereby allowing apredetermined amount of fluid to pass from the dash pot cylinderchambers into the displacement cylinder til, thus allowing the grindingwheel 28 to move forward under the pressure applied to the piston 36. Bycontrolling the rate of movement of the displacement rod M, the rate offeeding movement of the grinding wheel 25 may be readily varied asdesired. Ii? the displacement rod Qi is moved at a slow continuous ratetoward the left, a slow precise continuous infeed of the grinding wheel28 may be obtained. If the rod Si is moved intermittently toward theleft at slow intervals, a slow intermittent precise feeding movement ofthe grinding wheel 28 may be obtained.

The cylinder 83 is preferably connected so that the piston 82 will beactuated in timed relation with the actuation of the feed control valve43. A

to close the valve ing valve I88 which comprises a tle type valve I82 isrespectively with the exhaust pipe pipe 88 connects the valve chamberI8. with a chamber '88 formed at the right-hand end of the position ofthe valve 43 shown in the drawing, fluid within the cylinder chamber 88may exhaust through the pipe, through the valve chamber 16, and throughthe pipe 11 into the reservoir 12.

A pipe 81 is connected between the valve 43 and a check valve 88." Thecheck valve '88 is connected by a pipe 89 with a cylinder chamber 98formed at the left-hand end of the cylinder 83. In the position of thecontrol valve 43 illustrated in the drawings, fluid under pressure inthe valve chamber I may pass through the pipe 81, through the checkvalve 88 and the pipe 89 into the cylinder chamber 98 to move the piston82 into the position illustrated in the drawing.

During the forward, movement of the grinding wheel 28, it is desirableto control the rate of exhaust of fluid from the cylinder chamber 98 soas to provide the desired continuous rate of infeeding movement whendesired. A pipe III is connected between the pipe 89 and a piston typevalve 92 which is normally held in an open position by means of acompressionspring. A pull type solenoid 93 is provided automatically 92when desired in timed relationship with other mechanisms of ,the machinewhen it is desired to cut oi the exhaust of fluid through the pipe 9 IAn adjustable throttle valve 9| is provided in a pipe line 95 whichconnects the throttle valve 94 with the pipe 81. When fluid exhauststhrough the valve 92 and the throttle valve 94, it passes through thepipe 95 and the pipe 81- into a valve chamber 96 formed between thevalve pistons 81 and 48 when the valve stem 44 is in its left-hand endposition and passes out through the exhaust pipe 'I'I into the reservoir12.;

cylinder 83. In the Metering valve It is desirable during portions ofthe grinding operation to provide an intermittent flne precise feedingmovement of the grinding wheel 28. This is preferably accomplished bymeans of a meterhollow slidablymounted piston-type valve member I8I. Ashutslidably mounted within the valve member. IN. The valve member IN ispreferably actuated automatically by means of a piston rod I83 edcollars I85 and and a pair of adjustably mountl85 in a manner to behereinafter described. 1 An adjustable stop screw I86 is provided whichis-screw threaded into an end cap I81 which encloses the left-handendotthe valve member I84 The screw I86 serves to limit the movement of theshuttle valve I 81 and thereby to regulate the amount-of exhaust meteredfrom the cylinder chamber 98 of the cylinder 93. A pipe I88 connects thepipe 89' with ports I89 and H8 in the valve I88. A pair of exhaust portsIII and i I2 are connected by pipes '11. When an intermittent feed ofthe grindin matically in a manner to be hereinafter described so thatfluid under pressure exhausting from the cylinder chamber-'98 exhauststhrough the pipe '89, through the pipe I88, into the ports I89 and H8.The valve stem I83 is shown in its extreme the left automatically in amember 'I8I will move toward the left until a H3 and Ill wheel 28 isdesired, the valve 92 is closed auto'.

right-hand end position. When the valve stem v I83 is moved towardmanner to be hereinafter described, the valve port I I! coincides withthe port II8 so that fluid may exhaust from a valve chamber I I8 to movethe shuttle valve I82 I toward the left into-engagement with the stop"ment of the shuttle valve screw I88. This movement allows apredetermined quantity of fluid to exhaust from the chamber 98, therebyallowing a predetermined movement of the displacement rod 8| whichallows a predetermined forward feed of the grinding wheel 28. v

The valve I88 is illustrated on an enlarged scale to clarify theconstruction as compared with the cylinder .88 and associated parts.During the exhaust of fluid into the valve chamber IIB, a portion of thefluid within a chamber I I1 exhausts through a port I I8 and the port II I, through the pipe I I3 and the exhaust pipe 'I'I, into the reservoirI2. It should be noted that only enough fluid is exhausted from thechamber III to take care of the displacement caused by the move- I82toward the left. A similar operation is provided when the valve stem I83again moves toward'the right into the position illustrated in thedrawings. A predetermined quantity of fluid will be metered from thecylinder chamber 98 into the valve chamber III to move the shuttle valveI82 toward the right, thus allowing a predetermined infeed of thegrinding wheel 28,by a predetermined movement of the displacement rod8I.

Fluid motor I I9 is identical with that shown in the prior U. S.

patent to Wallace H. Wood, No. 2,212,871, dated August 27, 1940, towhich reference may be had for details of disclosure not containedherein. The motor II9 comprises a cylinder I28 which contains a slidablymounted piston I2 I The piston I2I is connected to the right-hand end ofa piston rod I22. A yoked member I23 is provided on the left-hand end ofthe piston rod I22 which straddles the valve stem I83 and is arranged inthe path of the collars I88 and I85. A suitable control valve isprovided automatically to reciprocate the piston I2I continuously,comprising a valve stem I26 which is fixedly mounted relative to ahollow slidably-mounted piston-type pilot valve I25. A shuttle typereversing valve I28 is slidably mounted within the hollow pilot valveI25. The valve stem I26 of the pilot valve I25 is provided with a pairof adjustably mounted collars I21 and I28 which are arranged to engagean upwardly extending portion I29 of the yoked member I29. The collarsI21 and I28 are actuated by movement of the piston Hi to determine thelength of the stroke of the piston I2I. This motor H9 is arrangedautomatically to transmit a reciprocatory motion to .the yoked memberI23 which in turn serves to actuate the metering valve -I88 in a, mannerhereinabove described.

A normally closed valve I38 is provided to control the admission offluid under pressure to the motor H9. .The control valve I38 is normallyheld in a downward or closed position by means of a compression spring.An electric solenoid I3I is provided which when energized will raise thevalve to admit fluid under pressure from the pipe I3 into a pipe I32whichadlnits fluid under pressure to the pilot valve I25 so as to startand continuously reciprocate the piston I2I. Fluid exhaust the cylinderchamber 98 into to provide an automatic intermittent from the motor H9,through a pipe 533, and through an adjustable throttle valve i243, intothe exhaust pipe ll, and returns to the reservoir l2. By adjustment ofthe throttle valve H36, the speed of.reciprocatory movement of thepiston l2i may be readily controlled so as thereby to control the rateof actuation of the metering valve 800 and thus provide either a, slowintermittent or a rapid intermittent feeding movement of the grindingwheel as desired.

To facilitate filling the dash pot cylinders and the reservoir 66, avalve M is connected'in the pipe line l3 which when open may pass fluidthrough a pipe MI and a ball check valve I42 into the dash pot cylindersand also through a pipe I66 into the reservoir 66. The valve I40 isutilized only when it is necessary to replenish fluid in the dash potsystem.

Gauge head In order precisely to control the work size, a gaugingmechanism is preferably provided such as that, for example, shown in thepatent to Shubel A. Foster, No. 2,267,559, dated December 23, 1941, towhich reference may behad for details of disclosure not containedherein. As shown in the drawing, this gauging device comprises a caliperI45 which is pivotally supported on a pivotally mounted bracket I46. Oneend of the bracket I46 is pivotally mounted on a wheel guard I41 whichsurrounds the grinding wheel 20. The caliper I45 is arranged to be swungfrom an inoperative position, as shown in the drawing, in a clockwisedirection, then downwardly, and then in a counterclockwise directioninto operative engagement with the work piece I being ground. When thework piece has been reduced to a predetermined size, electric contactsI48 within the caliper head are made to close a circuit which serves toenergize a relay I49 which is operatively connected to energize thesolenoid 93 and thereby close the valve 02 and thus stop the continuousinfeed or body feed of the grind-- ing wheel 20 into the work I5 and atthe same time serves to start a time delay relay I50.

Time relay The time delay relay I50 is a standard electrical relay suchas, for example, the Microfiex automatic instantaneous reset timermanufactured by the Eagle Signal Corporation of Moline, Illinois. Whenthe time relay I50 timing the period of dwell during which there is noinfeed of the grinding wheel 20 has completed a predetermined timeinterval, the time delay relay I50 serves to break a circuit and thusdeenergize the solenoid 50, thereby releasing the compression of thespring 69 which returns the feed control valve 63 into the positionillustrated in the drawing, thus admitting fluid under pressure into thecylinder chamber 4I of thecylinder 35 rapidly to move the piston 36together with the wheel slide 22 and grinding wheel 20 toward the rightinto an inoperative position.

A manually operable control lever H55 is provided for starting agrinding cycle or, if necessary, stopping the grinding cycle during agrindlng operation in case of emergency. The control lever I55 ispivotally mounted on astud 56 and is arranged so that when rocked in acounterclockwise direction, it will close a push button switch I5? tostart a grinding cycle. If it is desired to stop the grinding operationduring a grinding cycle, the control lever H55 ma be rocked in aclockwise direction to close a push to deenergize the relay I62.

button switch 852 which interrupts the grinding cycle and immediatelyand automatically returns the grinding wheel and its supporting slide toan inoperative position.

Operation The operation of thisimproved feeding mechanism will bereadily apparent from the foregoing disclosure. Assuming all of theadjustments have previously been made and a work piece I5 has beenloaded in an operating position ready for a grinding operation, theoperator rocks the control lever E55 in a counterclockwise direction toclose the push button start switch I51. This movement energizes a relayI60 which in turn serves to energize the solenoid 50 toshift the valvestem 40 of the feed control valve 43 toward the left to admit fluidunder pressure into the cylinder chamber 60 rapidly, to move the piston36, the wheel slide 22, and the grinding wheel 20 toward the left sothat it approaches the work piece I5. Before the grinding wheel 20engages the work piece I5, the flange 59 engages the dash pot pistons 56and 51 so that continued forward advance of the wheel is slowed down toa cushioning or shoulder feed in the case of a shoulder grindingoperation, the speed of which is governed by the setting of the needlevalve 64. The grinding wheel continues to advance at the cushioning feedor shoulder grinding feeduntil the screw 5| engages and closes the limitswitch 52. The closing of the limit switch 52 serves to energize a relayI 6| and a relay I62. Energizing of the relay I6I serves to energize thesolenoid 68 to close the valve 61, thus stopping the cushioning orshoulder grinding feed. Energizing of the relay I62 serves to energizethe solenoid 93 to close the valve 92, thereby preventing passage of oiltherethrough so as to prevent a body grinding feed being obtained.Energizing of the relay I62 also energizes the solenoid I3I to open thevalve I30 which allows passage of fluid under pressure through the pipeI32 to start the continuous reciprocation of the piston I2I which inturn serves intermittently to actuate the metering' valve I00. Themetering valve I00 allows an intermittent exhaust of a predeterminedamount of fluid from the cylinder chamber of the cylinder 83 which inturn withdraws the displacement plunger 8| a predetermined amount toproduce an intermittent advance of the grinding wheel by allowing aperiodic predetermined quantity of fluid to exhaust from the dash potcylinders through the pipe 84 into the displace ment cylinder 80.

The gauge head I45may now be placed in operative position in engagementwith the work piece l5. The intermittent feed of the grinding wheelcontinues'until the screw 53 engages and opens the limit switch 54 whichopens a circuit Deenergizing the relay I62 serves to deenergize thesolenoid I3i.

thus allowing the released compression of a spring to close the valveI30 to stop the intermittent infeed of the grinding wheel. At the sametime, deenergizing the relay I62 serves to deenergize the solenoid 93,thus allowing the released compression of a spring to open the valve 92to start a fine continuous body feed of the wheel toward the work axisby allowing fluid to exhaust from the cylinder chamber 90, through thepipe 9i, through the valve 92, and through the throttle valve 94 at arelatively slow rate. thuscausing a further continuous movement ofenigma until the work has been reduced to a predeter mined size at whichtime. the contacts Its in the gauge I45 close to energize the relay I49.Energizing the relay I49 serves to energize the solenoid 93 to close thevalve 92 and thereby shut ofi the body feed of the grinding wheel 22. Atthe same time, energizing of the relay I49 sets the time delay relay I50in motion to control the sparking-out or finish grinding or the workpiece I while the wheel 2!! is held against further forward feedingmovement. The finish grinding or sparking-out period continues for apredetermined time interval as gove ned by the relay I50. After thepredetermined time interval has elapsed, the time relay I50 deenergizesthe relay I60 which in turnserves to demergize the solenoid5Il,'-thereby releasing the compression of the spring 49 which in turnmoves the valve stem 48 toward the right to position the valve parts inthe position shown in the'drawing. This shifting movement of the valve63 serves to pass fluid through the pipe 42 into the cylinderchamber 4Irapidly to move the piston 36, the grinding wheel slide 22, and thegrinding wheel 20 toward the right into a rearward or inoperativeposition,-thus terminating the grinding cycle. a p

when the timer I59 operates to deenfergize the relay limit also is'operatively connected to deenergize the'relays I49 and IBIrespectively. Deenergiaingof'the relays I49 and IGI serves todeenergiz'ethe solenoid 68 and the solenoid 93 to open thevalves 61 and92 respectively. Th gauge is then removed from engagement with thework'and the gauge contacts are automati cally'broken or reset for the nextgrinding operationand the electric timer I5Ii automatically resets readyfor the next grinding cycle. The

finish ground work piece I5 may then be removed from the machine andreplaced by anew work iece tobe ground, after which the next grindingcycle may be initiated by actuation of the control lever I55 in a mannerhereinab'ove d'escribe'd.-

It will thus be seen that-there has been prof therefor, means includinga pisten and cylinder rapidly to move said slide, means including a dashI pot feed regulator to slow down the rapid appreaching to a relativelslow continuous feedin movement for a shoulder grinding operation,electrical control means rendered operative after a predetermined slowfeed intermittently to produce a fine intermittent body feed, to roundup the cylindrical surface being ground, a work sizing gageautomatically to stop the forward feed for a predetermined timeinterval, and an electrical time delayrelay operatively connected toreturn said slide and grinding wheel to an inoperatfi'e position after apredetermm' ed period of 3. In a grinding machine having a rotatablegrinding wheelna transversely movable slide 1 therefor, meansIin'cludinga piston and cylinder rapidly to move said slide; means including a,dash pot feed regulator to slow down the rapid approaching to arelatively slow continuous feeding movement, means rendered operativeafter the wheel reaches a predetermined position intermittently toexhaust fluid from said regulator to produce a fine intermittent feed ofthe grinding wheel, means to control continuous exhaust fluid from saidregulator to produce a fine continuous plunge-cut feed, meansautomatically to stop said feed for a predeterminedtime interval, and anelectrical time delay relay operatively connected to return said slideand wheel to an inoperative position after said time interval haselapsed,

4. In a grinding machine having a rotatable 'grinding wheel, atransversely movable slide .movement for a shoulder grinding operation,

means rendered operative after the wheel reaches a predeterminedposition intermittently to ex haust fluid from said regulator .toproduce a fine 1 intermittent feed of the grinding wheel to round up thecylindrical surface being ground, means to vided by this inventionapparatus in which the various objects hereinabove set forth togetherwith many thoroughly practical advantages are successfully achieved. Asmany possible embodiments may be made of: the above invention and asmany changes might be made in the embodiment above's'et forth, it is tobe understood that all matter hereinbefore set forth or shown in theaccompanying drawing is to be interpreted as illustrative and not in a,limiting sense.

Iclaimz. g 1. In a grinding machine -'having a rotatable grinding wheel,a transversely movable slide,

therefor, means including a piston and cylinder rapidly to move saidslide, means including a dash pot feed regulator to slow down the rapidapproaching to a relatively slow continuous feed mg movement, electricalcontrol means rendered operative after a predetermined slow feedintermittently to produces. fine intermittent feed to round up thesurface being ground, meansto stop the forward feed for a predeterminedtime interval, and an electrical time delay relay operatively connectedto return said slide and grinding wheel to an inoperative position aftera, predetermined period of dwell.

2. In a grinding machine having a rotatable grinding wheel, a terselymovable slide control continuous exhaust of fluid from said legulator toproduce a fine continuous plunge cut feedto reduce said surface to apredeteed size, means automatically to stop said feed for apredetermined time interval, and an electrical time delay relayoperatively connected to return said slide and wheel to an inoperativeposition after said time interval has elapsed.

5. Ina grinding machine having a rotatable grinding wheel, atransversely movable slide therefor, means including a piston andcylinder rapidly to move said slide, a. control valve therefor, meansincluding a dash. pot feed regulator to slow down the'rapid approachingto a relatively 'slow shoulder grinding feed, means to intermit= tentlyexhaust fluid from said regulator to pro duce a, fine intermittent feedto round up the work, means continuously to exhaust fluid] from saidregulator to produce a fine continuous feed 6. In a grinding machinehaving a rotatable emise minding wheel, a transversely movable slidetherefor, means including piston and cylinder rapidly to move saidslide, a control valve therefor, means including a dash pot feedregulator to slow down the rapid approaching to a relatively slowshoulder grinding feed, means intermittently to exhaust fluid from saidregulator to produce a fine intermittent feed to round up the work,means continuously to exhaust fluid from said regulator to produce aflne continuous feed of the grinding wheel relative to the work, meansauto matically to stop said continuous feed when the work has beenreduced to a predetermined extent, a time delay relay which is set inmotion when the continuous feed is stopped while maintaining th grindingwheel in grinding engagement with the work for a predetermined finishgrinding period, and means actuated by said relay after a predeterminedtime interval to shift said control valve and thereby terminate thegrind ing operation. 7. In a grinding machine as claimed in claim 5, thecombination with the parts and features therein specified, of adisplacement cylinder and rod to control the exhaust of fluid from saiddash not feed regulator, a hydraulic piston and cylinder to actuate saiddisplacement rod so as to increase or decrease the capacity of saiddisplacement cylinder, means intermittently to exhaust a predeterminedamount of fluid from said hydraulic cylinder intermittently to move saiddisplacement rod so as to produce a feeding movement of the grindingwheel, and means including a throttle valve continuously to exhaustfluid from said hidraulic cylinder continuously to move saiddisplacement rod so as to produce a fine continuous infeed of thegrinding wheel.

8. In a grinding machine as claimed in claim 5, the combination with theparts and features therein specified, of means including a displace-,

ment cylinder and rod to control the rate of exhaust of fluid from saiddash pot feed regulator, a hydraulic piston and cylinder to actuate saidplacement rod so as to increase or decrease the capacity of saiddisplacement cylinder, means including a metering valve to meter theexhaust of fluid from said hydraulic cylinder, a continuously actuatedfluid motor to actuate said metering valve to provide an intermittentinfeed of the rinding wheel, and a normally open solenoid valve to startand stop said motor.

9. In a grinding machine as claimed in claim 5, the combination with theparts and features therein specified, of means including a displacementcylinder and rod to control the exhaust oi fluid from said dash pot feedregulator, a hydraulic piston and cylinder to actuate said displacementrod so as to increase or decrease the capacity of said displacementcylinder, 2, metering valve to meter the exhaust of fluid from saidhydraulic cylinder, means including a continuously actuated fluid motorto actuate said metering valve so as intermittently to move saiddisplacement rod to pr uce an intermittent feed of the grinding wheel, asolenoid valve to start and stop said motor, means including a solenoidvalve to start and stop the continuous exhaust of fluid from saidcylinder, and means including a throttle valve to regulate saidcontinuous exhaust of fluid from the hydraulic cylinder to produce thedesired continuous infeeding movement of said grinding wheel.

10. In a grinding machine as claimed in claim 5, the combination withthe parts and features therein specified, of means including adisplaceing valve to meter the exhaust of fluid from said.

- hydraulic cylinder, means including a continuously actuated fluidmotor to actuate said metering valve so as intermittently to move saiddis-.-

l placement rod to produce an intermittent feed of the grinding wheel, anormally closed solenoid valve to start and stop said motor, meansincluding a normally open solenoid valve to start and stop thecontinuous exhaust of fluid from said cylinder, and means including athrottle valve to regulate said continuous exhaust of fluid from thehydraulic cylinder to produce the desired continuous infeeding movementof said grinding wheel. J

11. In a grinding machine as claimed in claim 5, the combination withthe parts and features therein specified, of means including adisplacement cylinder and rod to control the exhaust 01' fluid from saiddash pot feed regulator, a hydraulic piston and cylinder to actuate saiddisplacement rod so as to increase or decrease the capacity of saiddisplacement cylinder, a metering valve to meter the exhaust of fluidfrom said hydraulic cylinder, means including a continuously actuatedfluid motor to actuate said metering valve'so as intermittently to movesaid displacement rod to produce an intermittent feed of the grindingwheel, a normally closed solenoid valve to start and stop said motor,means including a throttle valve to regulate the continuous exhaust offluid from'the hydraulic cylinder to produce the desired continuousinfeeding movement of said grinding wheel, means including a normallyopen solenoid valve to start and stop con- 40 tinuous exhaust of fluidfrom said hydraulic cylinder, and electrical control meanssimultaneously to actuate said solenoid valves so as to render operativeeither an intermittent or a continuous feed of the grinding wheel.

12. In a grinding machine having a rotatable grinding wheel, atransversely movable slide therefor, means including a piston andcylinder rapidly to move said slide, a solenoid actuated control valvetherefor, means including a dash pct feed regulator having a needlevalve to slow down the rapid approaching to a relatively slow shouldergrinding feed, a solenoid valve to cut oil fluid exhausting through saidneedle valve to stop the shoulder grinding feed, a limit switch actuatedby movement of said piston, an electric relay operatively connected withsaid switch and solenoid valve to close the solenoid valve when thelimit switch is closed, means including a solenoid valve to start andstop an intermittent feed of the grinding wheel to round up the work,means including a solenoid valve to start and stop a continuous infeedof the wheel to size the work, a second relay which is actuated by theclosing of said limit switch to actuate the second and third 5 solenoidvalves o as automatically to start an intermittent feed of the grindingwheel when the shoulder grinding feed is terminated to' round up thework, a limit switch which is opened after a further continuous feedingmovement to actuate the second and third solenoid valves to terminatethe intermittent feed and to start a fine continuous feed, a workgauging device including a normally open switch which is closed when thework is ground to a predetermined size, a relay actuated thereby toterminatesaid continuous feed,

- 2 2 and an electfical time delay reley which is eet in e mehien byclbsmg said gauging device ewitch te central the duration of a,predeizermined finish grindingnoperation, said time relay after e predetermined time interval serving to deenergize said seleneid controlvalve to cause e reerwerd mevement of the grinding wheel and thus termia, grinding cycle.

JOHN E. mmemm The fellewmg reiferencee ere ef xrecerd in the file ofthis patent:

eemaee Number 2,082,?26 5 2,113,361 2,1163% 2,1.'-2,02E% 2,267,391zgeemee m 2,37%,237

